Just as many people have become habituated to having Internet access all the time at home (remember the dialup days when connections were metered?), people are used to having their smart phones and iPads with them all the time.
Yeah you can say you want to get away from it all for vacations but how much of our use of computers and mobile devices is for leisure, as opposed to for work?
I check my work emails on my iPhone while on vacation, using data that I've paid for. But I rarely if ever reply to any of them. But I get the data because I use it for a lot of other things.
For instance, I used it with Google Maps to navigate northern Italy. Didn't have to pack a Garmin. And often, the mobile network provided faster speeds than the hotel Wifi in many cases.